The present invention relates to fixed dental prosthetic devices, and more particularly to cranial motion dental attachments for linking the interproximal walls of adjacent cast crowns while permitting relative movement therebetween.
Before recent developments in cranial studies, little attention was given to the cranial bone structure and the movements therebetween particularly as it concerned the field of dentistry. Dental attachments and prosthetic devices were placed to provide rigid connections between natural teeth and artificial crowns and bridge structures. Advances in craniology have taught that the cranial bones are not rigidly connected, but rather are formed by a series of individual bones interconnected by sutures and that these individual bones move relative to each other during normal body functions such as primary and secondary respiratory motion (breathing), eating and so forth.
Rigid dental attachments directly inhibit this motion causing various reactions generally detrimental to the normal physiologic functions of the cranium, cerebrospinal fluid flow, cranial dural membrane, upper cervical vertebrae, and neuromuscular systems. Rigid attachments also create proprioceptive and physiologic stress between adjacent members of the dental structure which can result in loosening of the supporting structures.
The general problems caused by rigid dental attachments has been addressed in the patents to Morton, 2,129,861 and 2,227,735, and to Weissman, 3,530,582. These patents are directed to lock pins between adjacent dental prosthetic devices and use spherical ball and socket type joints which permit rotational movement between the adjoining structures but do not allow lateral movement.
The present invention is directed to a cranial motion dental attachment which differs from the prior art devices and allows lateral motion between adjacent dental structures. The cranial motion dental attachment was specifically designed for mid-line connections between the maxillary central incisor teeth. The attachment enables horizontal micro-motion of the maxilla as occurs during normal respiratory inhalation while preventing buccal, lingual and gingival torquing forces. The attachment is equally applicable to other sutural locations where cranial micro-motion and normal bone flexibility occurs between adjacent dental structures.
The cranial motion dental attachment takes the form of a piston having an integral retainer body attached to a dental structure and a cylinder attached to an adjacent dental structure adapted to receive the piston so that the piston is moveable within the cylinder permitting horizontal or lateral movement between the adjacent dental structures.
Among the objects of the present invention is the provision of an improved dental prosthetic attachment permitting lateral movement between adjacent dental structures while providing a suitable interconnection between the adjacent dental structures, and the provision of a cranial motion dental attachment which is simple in structure and easily installed in dental prosthetic devices.
Other objects, features and advantages of the present invention will be fully appreciated by referring to the accompanying description of preferred embodiments, as well as the drawings.